Daisuke Matsuzaka, Improving Via Injury?

In only 26 of Daisuke Matsuzaka’s 110 career starts has he walked 5% or less of the batters faced. And 3 of those 26 starts came in June.

Daisuke has gone back to the DL since his brief five-start appearance, and it appears the Boston faithful have begun to doubt the Japanese import will provide much more value to the Red Sox this season or perhaps at all:

Valentine said they wanted to leave Matsuzaka sidelined until his neck pain had completely gone away. It’s anybody’s guess how long that will take. In theory he could return later this month or maybe he never pitches for the Sox again.

[emphasis mine]

Many in Boston are expecting Daisuke will be non-tendered after this year and will have to seek employment elsewhere. Given Daisuke’s recent injuries, maybe that’s the right financial decision (he could potentially be brought in on a cheaper deal than what he’d get in arbitration). But looking at the numbers from Daisuke’s five 2012 starts, we find the 31-year-old righty appears to have some good starts left yet.

Before leaving his fifth start with neck tightness, Daisuke had a 1.13 xFIP. Sure, his 5.23 FIP — a product of too many home runs allowed — was not great, but home runs have never been much of a problem for Daisuke; the walks have. And over those first four starts off the DL, Daisuke walked only 6.6% of total batters faced while striking out 22.0%.

He currently owns an 11% BB-rate on his career; that’s good enough to tie for the 8th-worst among qualified starting pitchers since 2007. But he also had the best FIP-minus among those 10 worst pitchers — a credit to his ability to limit home runs and strike out a decent amount of batters. If Matsuzaka can reduce his walk rate — even a little — he can potentially pitch at level acceptable, if not above average, for a third or fourth starter.

Looking back a Daisuke’s game logs, we see, as noted at the beginning, that three of his most recent five starts were exceptional. How exceptional?

If we limit his game logs to just the games where he finished 5.0 IP or more, we find he has 24 games out of 95 with a BB-rate at or under 5% — that is, in this case, games where he walked 0 or 1 batters.

We also find that 11 of those 24 games came in 2007, which means most of them. And in recent years, they have been a rarity:

In other words, the heartiest chunk of these low-walk games came in 2007 — his first and arguably best year in the league (92 FIP-, 3.99 SIERA). If we look at the low-walk starts per total number of games started, we see once again his recent success sticks out noticeably:

5.0 IP, Less-Than-2-Walks Starts per Total Starts

Year    Percent of Total Starts
2007:   34%
2008:   7%
2009:   17%
2010:   21%
2011:   14%
2012:   60%

So, in short, these first few, good starts are peculiar. In 2012, he has already had more low-walk starts than in 2008, 2009 or 2011 — and all with fewer games pitched.

Could it be an issue of distribution? A well-timed lucky streak? Quite possibly. There is a good chance that after or during his next five starts, the league will adjust to him, become more patient and resume walking at a normal rate.

Still, his PITCHf/x Plate Discipline numbers suggest he has one of the best Zone% of his career at 53%. Last year, he was at 49.6%. That’s about the difference of about 6 pitches over the course of a 100-pitch start. Is that enough to reduce his walk rate significantly? I don’t know. Bartolo Colon (3.9% BB-rate) leads the league with a 60.4% Zone-rate, while Randall Delgado (11.0% BB-rate) is last among qualified pitchers with a 39.4% Zone-rate. A 53% Zone-rate would rank Matsuzaka as the 11th highest Zone-rate in the league.

If he truly can (and chooses to) maintain that rate, he could very well be a late-season weapon for the Red Sox. And if he can maintain that low walk rate while keeping his homers down and his strikeouts up, maybe he could pitch 10% better than league average for 150 or so innings — that’s a 3 WAR pitcher. At that level, Matsuzaka for $12 million, or so, might actually be a bargain.